Hydraulic transmission system



All@ l, 1939. H. J. KErrEL 2,158,215

HYDRAULIC TRANSIISSION SYSTEM Filed July 25, 1956 2 Sheets-Sheet 1 -Eyf I4 /e /7 ,0 Q 20 2. 2 V

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/7 .as /25 v jrzuenfo Patented Aug. 1,' 1939 UNITED "STATES PAT-ENT' OFFICE 2,168,215 nYDaAULIo *rnANsMissIoN SYSTEM.

Application July 23, 1936, serial No. 92,116 lIn Germany lAug-ust 1, 1935 12 Claims.

The present application relates'to hydraulic I l0 -sides in the provision oi an apparatus of the type set forth having a plurality of pistons which are flexibly and resiliently connected with their respective piston rods.

Another object of this invention is the provi- 3 sion of an apparatus of the type set forth com-3. prising rack and tooth wheel provisions, whereby -the rack is adjustably and resiliently pressed to the tooth wheel. A

A further object of this invention is to provide an apparatus of the4 type set forth having aplu;-

rality of cylinders, the ends of which are closed by flexible means. y,

Another object of the present invention resides lin the provision of an apparatus of the type disclosed having a plurality of cylinders, the interior volume of which can be simultaneously changed. Further and other objects of the present invention will be hereinafter set forth in the accompanying specification and claims and shown in the d'rawings which, by way of illustration, show what I now consider to be a preferred embodiment of my invention.

In the drawings:

Fig. 1 is a cross sectional showing of a hydraulic sending and receiving apparatus according to the present invention.

Fig. 2 is a cross sectional showing of a detail shown in Fig. 1 and Itaken along line 2-2 of Fig. 1.

Fig. 3 is a modification of the lower part of the apparatus shown in Fig. 1.

Fig. 4 is another, modification of the lower part i of the apparatus shown in Fig. 1. Fig. 5 is another modication of the lower part of the apparatus shown in Fig. l.

Fig. 6 is a diagrammatic showing of the application of my present invention to aircraft.

Like parts are designated by like numerals in A, all gures of the drawings.

'I'he apparatus consists substantially bf a closing plate I, the pump body 2, the upper part 3, and t e closing cap 4. In the pump body 2 are two o rating cylinders which are parallel to one 55' another and in which pistons 5 and 6 are mov- (Cl. Gil-54.6)

ably arranged. 1 and 8 are the Aconnections oi t'ube lines with cylinders 5 and 6', respectively,

. which tube lines individually connect said cylinders with the cylinders of another like apparatus. The upper 4part 3 carries a shaft 9 to which a 5 lever II -is connectedby means of keylll. If the apparatus serves as sender, lever II may be operated by hand; if it serves as receiver, the parts to be controlled are connected to lever 'II, for example, when applied to aircraft, a rudder or the 10 like. A tooth wheel I2 which engages the racks I3 and I4 isalso keyed to shaft 9. These racks are only pressure transmittingly but not rigidly connected with pistons 5 and 6;. for this purpose, llin g\members I5 and I6 made of rubber or the like are arranged between the lower ends of racks I3 and I4, respectively, and the pistons 5 and 6, respectively. The advantage of the use of such resilient filling members resides in the fact that minor inaccuracies in the assembly of the appa- N ratus have no harmful influence on its operation and that the connection between piston and rack is easy and inexpensive to`manufacture. The racks I3 and I4 are pressed to .tooth wheel I2 by y means of gliding members I1 and I8, respective- 25 ly. .One of these members, namely, member I'I is shown in another longitudinal section in Fig. 2. The end of the member is provided with a prismatic reset 33 into which the prismatic back portion of rack I3vfts so that member I1 cannot revolve. Members I1 and I8 are able to reciprocatingly move in the upper part 3. They are pressed towards the racks I3 and I4 by springs I9 and 20, the tension of which can be adjusted by manipulation of screws 2l and 22. These screws are prevented from undesired turning by means. of locks 23 and 24. The 'gliding members I1 and I8 which are adjustingly pressed to racks I3 and I4 not onlyassure engagement of said racks with tooth wheel I2 but also act as brakes and prevent undesired motion of pistons 5 and 6.

In between the pump body '2 and the closing plate I, a plate 25 made of rubber or another. elastic material is arranged. This plate 25 closes 45 the lower ends of cylinders 5' and 6 and can be deformed by manipulating nut 26" in such manner that the'interior volu'me of both cylinders is simultaneously increased or decreased, Iif a member 28' is used according to Fig. 3, or so that 50 the interior volume of one of the cylinders is increased and, at the same time, the vvolume of the other cylinder decreased, if a `member 23 is used as shown in Flg..1,' Nut 26 in Fig. 1 is prevented from axial movement by` cam 34 of mem- 55 ber 21 which-is xed to plate I. Member .28 is slidngly carried by means of plate I and has a screw extension 35 cooperating with nut 26; upon turning nut 26, member 251s moved laterally; member 28 has two resets which comprise surfaces 28 and 30 which are inclined in opposite directions; plate I has two openings 36 and 31 which are opposite said resets and in`which openings and resets balls 3| and 32 are situated. Upon lateral movement of member 28, for example to the right as seen in Fig. 1t, ball 32 is forced upwards by the surface 30, whereas ball 3I is permitted to move downwards. Flexible plate l25, due to the'pressure inside of cylinders 5' and 6' follows the movements of balls 3I and 32, and the interior volume of cylinder 5 is increased, whereas the volume of cylinder 6' is decreased. The deformations of plate 25 are indicated in dotted lines in Fig. l. the left as seen in Fig. l, the volume of cylinder 5' is decreased and that of cylinder 6' increased. Such additional operating means which, in fact, are used as adjusting means are desirable, for

example, when the apparatus is used in -con- 'nection with a control system as shown in Fig. 6. If sender 5 I is provided -with the adjusting means shown in Fig, l and member 28 is moved to' the left, more operating liquid is forced into tube line 55 and liquid is permitted to flow from line 56 into the right cylinder of apparatus 5I', whereby lever 54 is turned counterclockwise and the initial position of said lever and the throttle 4l) connected thereto is changed accordingly. Of course, for lnormal operation of the throttle 40 lever 5I is operated. Nut 26 is manipulated only for' initially setting the position of lever 54 with respect to lever 5I.

If the surfaces 29 and 30 are inclined in the same direction as are the surfaces 29' and 30' of member 28' shown inFlg. 3, then the volume of both cylinders 5' and 8' is increased or decreased simultaneously upon lateral movement of part 28'.' Such an adjustment is desirable, forexample, when there is too much clearance between the racks I3 and I4 and the wheel I2. ment of member 28' to the left, the gear is tightenedf'up and the degree of tightening can be adjusted very finely.

If resilient members 3I' and 32' as shown in Fig. 4 are arranged in between plate 25 and member 28, the resilient closures of cylinders 5 and 6 act as safety means against undired high pressures in the interior of the hydraulic transmission gsystems. For example, if there is an excess pressure in the tube line connected to nipple 1, then elastic plate 25 is depressed against the action of spring 3|' and nq great damage can be done by the excess pressure.

Instead of the elastic plate 25, pistons 3I and 3 2'1' may be arranged which are guided in the operating cylinders 5' and 5", and the position of which pistons can be adjusted by turning a cam shaft 38 by means of the hand wheel 26' as i's shown in Fig. 5. According to the conguration and position of cams 29 and 30" with respect to shaft 38, these cams act as the maimed surfaces 29 and 38 in Fig. 1 or 29-and 30' in Fig. 3.

Fig.6 diagrammatically shows my invention as described in the foregoing paragraphs and as used in aircraft for controlling the gas supply control levers 39 and 40 of the engines 43 and 44 driving propellers 45 and 46. The levers 5I and 52 correspond to lever II in Fig. 1 and are manipulated by the operator of the plane. From the hydraulic senders 5I'Vand 52', pipe lines 55 If member 28 moves toI By moveand 55 and 51 and 58 lead to the hydraulic receivers 54 and 53', respectively. These pipe lines correspond to the pipe lines connected to nipples 1 and 8 in Fig. 1. lUpon operation of, for example, lever 5I of sender 5I',.,lever 54 of receiver 54', which also corresponds to lever II in Fig. 1, makes the same movement as lever 5I and, by means of connecting rod 42, adjusts the gas control lever 48; upon movement of -lever 52 of sender 52', lever 53 of receiver 53' makes the same movement as lever 52 and adjusts gas supply-lever 38 which is connected to lever 53 by means of connecting rod 4I. l

While I believe the above described embodiments of my invention to be preferred embodiments, I wish it` to be understood that I do not desire to be limited to the exact details of design and construction sho'wn and described, for obvious modifications will occur to a person skilled in the art.

What I claim is: 1. A hydraulic control apparatus, comprising a `plurality of operating cylinders made of rigid material, pistons made of rigid material within said cylinders, a tooth wheel and a plurality of racks engaging said tooth wheel; and connecting means made of rubber like material and interconnecting said racks and engaging said pistons, whereby said pistons are operated upon motion of said,

tooth wheel, and, due to said connecting means, minor, independent movements of said pistons are possible, and minor inaccuracies in the assembly of the apparatus remain without in uence.

2. A hydraulic control apparatus, comprising a plurality of operating cylinders, pistons within said cylinders, a tooth wheel and a plurality of racksl engaging said 4tooth wheel, said pistons having a cup-like vconiiguration, and means made of yielding material and being situated inside said cup-like pistons and abuttingly cooperating therewith and being connected with said racks, whereby said pistons are operated upon motion of said tooth wheel, and, due to said yielding means, minor, independent movements of said pistons are permitted, and minor inaccuracies in the assembly of the apparatus remain without infiuence.

3. A hydraulic control apparatus comprising a plurality of operating cylinders, pistons within said cylinders, a tooth wheel and a plurality of racks engaging said tooth wheel and connected to and operatingl said pistons upon motion of said tooth wheel, and brake means resiliently and glidingly engaging said racks and being adapted to simultaneously press said racks to said tooth wheel, whereby a braking effect is also produced which prevents undesired movements of said racks, in longitudinal direction and definite engagement of said racks and said tooth wheel is assured whereby undesired movement of said racks in a transverse direction is eliminated.

4. AA hydraulic control apparatus comprising a plurality of operating cylinders which are hydraulically independent from one another, pistons within said cylinders, a tooth wheel, a plurality of racks engaging said tooth wheel and connected to and operating' said pistons upon motion of said tooth wheel, a movable, adjustable closure at one end of each cylinder, and an operating means operatively connected with all of said closures and adapted to simultaneously move said closures, whereby the interior volume of said cylinders is changed.

5. A hydraulic control apparatus comprising a plurality of operatingA cylinders which are hydraulically independent from one another, pistons within said cylinders, a tooth wheel, a plurality of racks engaging said tooth wheel and connected to and operating said pistons upon motion of said tooth wheel, a movable, adjustable closure at one end of each cylinder, and an operating means operatively connected with all of saidclosures and adapted to simultaneously move all of said closures in the same direction, whereby the interior volume of all of said cylinders is changed in the same direction, i. e., increased and decreased.

6. A hydraulic control apparatus comprising a plurality of operating cylinders which are hydraulically independent from one another, pistons within said cylinders, a tooth wheel, a plurality of racks engaging said tooth wheel and connected to and operating said pistons upon motion of said tooth wheel, a movable, adjustable closure at one end of each cylinder, andan operating means operatively connected with all of said closures and adapted to simultaneously move some of said closures in one direction and the other closures in the opposite direction, whereby the interior volume of some of said cylinders. is

increased and the interior volume of the other some of said cylinders is decreased.

'l A hydraulic control apparatus comprising a plurality of operating cylinders which are hydraulically independent from one another, pistons within said cylinders, a tooth wheel, a plurality of racks engaging said tooth wheel and connected to and operating said pistons upon motion o! said tooth wheel, a resilient closure at one end of each cylinder which yields to excessive pressures inside of said cylinders.

8. A hydraulic control apparatus comprising a plurality of operating cylinders which are hydraulically independent from one another, pistons within said cylinders, a tooth wheel, a plurality of racks engaging said tooth Vwheel and connected to and operating said pistons upon motion of said tooth wheel, and a movable, adjustable, and resilient closure at one end of each cylinder, by means of which closures the interior volume of said cylinders can be changed, and which closures yield to excessive pressures inside of said cylinders.

9. A hydraulic control apparatus comprising a plurality of operating cylinders which are hydraulically independent from one another, pistons within said cylinders, a tooth wheel, a plurality oi' racks engaging said tooth wheel and connected to and operating said pistons upon motion of said tooth wheel, and a yieldingly movable adjustable closure at one end of each cylinder, by means of which closures the interior volume of said cylinders can be changed.

10. A hydraulic control apparatus comprising a plurality of operating cylinders which are hydraulically independent from one another, pistons within said cylinders, a tooth wheel, aplurality ci' racks engaging said tooth wheel and connected to and operating said pistons upon motion of said tooth wheel, and a, closimq' member common to a plurality of said cylinders and individually, movably and adjustably individually closing one end of each cylinder which is closed by said member, by means of which closure the interior volume of those of said cylinders which are closed by said member can be changed.

11. A hydraulic control apparatus comprising a pair of operating cylinders which are hydraulically independent from one another, a piston within each of said cylinders, a tooth wheel, a pair of racks engaging said tooth wheel and being individually connected to and operating said pistons upon motion oi! said tooth wheel, a movable adjustable closure at'one end of each cylinder, and an operating means operatively connected with said closures and adapted to simultaneously move one of said closures in one direction and the other closure in the opposite direction, whereby the interior volume of one of said cylinders is increased and the interior volume of the other one of said cylinders is decreased.

l2. A hydraulic control apparatus, comprising a plurality oi operating cylinders, which are hydraulically independent from one another, pistons within said cylinders, a tooth wheel, a plurality of racks engaging said tooth wheel and connected to and operating said' piston upon motion of said tooth wheel, and a stationary end cover having a ilexible, adjustable part 'and being disposed at one extreme end of each cylinder for making minor adjustments o! the interior volume of said cylinders.

HANsJULIUsmm 'w 

